Bathtub



FIG. 1 is a top plan view of a bathtub showing the new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof; and,

FIG. 5 is a side elevational view thereof. 

The ornamental design for a bathtub, as shown and described. 